Method for creating ultra-high-density holes and metallization

Abstract

Methods and apparatuses directed to high density holes and metallization are described herein. A method may include providing a dielectric layer including a plurality of holes, forming a fill material over a top surface of the dielectric layer and in the plurality of holes, and reflowing the fill material to substantially remove any voids in the plurality of holes. Other embodiments are also described.

1. A method comprising:
 forming a sacrificial layer on a substrate; 
 forming a mask layer on the sacrificial layer; 
 patterning the mask layer to form a plurality of mask lines and to reveal first portions of the sacrificial layer; 
 patterning the plurality of mask lines to (i) form a plurality of mask islands by removing portions of the plurality of mask lines and (ii) reveal second portions of the sacrificial layer, the second portions being revealed by removing the portions of the plurality of mask lines; 
 removing the revealed first and second portions of the sacrificial layer to form a plurality of pillars of the sacrificial layer, wherein ones of the plurality of pillars are disposed between corresponding ones of the plurality of mask islands and the substrate; 
 forming a dielectric layer on the sacrificial layer around the plurality of pillars; 
 removing the plurality of mask islands and the plurality of pillars to form a corresponding plurality of holes in the dielectric layer; 
 forming an electrode to fill a portion of at least one hole of the plurality of holes in the dielectric layer; and 
 depositing a phase change material to substantially fill a remaining portion of the at least one hole that is not filled by the electrode. 
 
     
     
       2. The method of  claim 1 , further comprising forming a liner layer over the plurality of pillars after the removing of the revealed first and second portions, wherein the dielectric layer is formed on the liner layer around the plurality of pillars. 
     
     
       3. The method of  claim 1 , wherein the patterning the mask layer comprises exposing the mask layer with a first photomask including a first plurality of lines, and wherein the patterning the plurality of mask lines comprises exposing the plurality of mask lines with a second photomask including a second plurality of lines. 
     
     
       4. The method of  claim 1 , wherein the second photomask comprises the first photomask rotated 90°. 
     
     
       5. The method of  claim 1 , wherein the dielectric layer is formed on the sacrificial layer to gap-fill an area between the plurality of pillars.